We use A Baby's Best Friend (www.abbf.com) every time we are at WDW. They are FABULOUS! Their cribs are CLEAN, and the convenience is great. WE use them for lots of other things than just the crib, and it is the best money we spend on vacation!
I'll vote for A Baby's Best friend too! We rented a crib and toys. Everything was clean and in great shape! We're planning on using them again on our next trip if DD is not using a "real" bed by then.
We rented a crib from A Baby's Best Friend as well. It was well worth the expense, because nobody would have slept if DD had to sleep in a Pack n Play!